Synesthesia & Factors?

The girl says that the number 20 has a colour that is a mix of the colours of 20's factors. I find this interesting, because I always thought arithmetic is imaginary, right? If she didn't learn basic arithmetic, would 20 have had the same colour? Or would 20 have the same colour, but to her, the colour would seem random to her?

The girl says that the number 20 has a colour that is a mix of the colours of 20's factors. I find this interesting, because I always thought arithmetic is imaginary, right? If she didn't learn basic arithmetic, would 20 have had the same colour? Or would 20 have the same colour, but to her, the colour would seem random to her?